| 31 Aug 17 | C. Donaldson Clayton Donaldson |  Birmingham CityBIR | → |  Sheffield UnitedSHU | Undisclosed |
| 31 Aug 17 | B. Heneghan Ben Heneghan |  MotherwellMOT | → | Sheffield UnitedSHU | Undisclosed |
| 31 Aug 17 | J. Brayford John Brayford | Sheffield UnitedSHU | → |  Burton AlbionBRT | Free |
| 31 Aug 17 | B. Heneghan Ben Heneghan | MotherwellMOT | → | Sheffield UnitedSHU | Undisclosed |
| 25 Aug 17 | C. Carter-Vickers Cameron Carter-Vickers |  Tottenham HotspurTOT | → | Sheffield UnitedSHU | Loan |
| 25 Aug 17 | C. Carter-Vickers Cameron Carter-Vickers | Tottenham HotspurTOT | → | Sheffield UnitedSHU | Loan |
| 03 Aug 17 | M. Done Matt Done | Sheffield UnitedSHU | → |  RochdaleROCH | Undisclosed |
| 27 Jul 17 | J. Blackman Jamal Blackman |  ChelseaCHE | → | Sheffield UnitedSHU | Loan |
| 27 Jul 17 | J. Blackman Jamal Blackman | ChelseaCHE | → | Sheffield UnitedSHU | Loan |
| 25 Jul 17 | J. Lundstram John Lundstram |  Oxford UnitedOXF | → | Sheffield UnitedSHU | Undisclosed |
| 17 Jul 17 | J. Wilson James Wilson | Sheffield UnitedSHU | → |  WalsallWAL | Loan |
| 11 Jul 17 | L. Reed Louis Reed | Sheffield UnitedSHU | → |  ChesterfieldCHES | Loan |
| 07 Jul 17 | C. Hussey Chris Hussey | Sheffield UnitedSHU | → |  Swindon TownSWI | Loan |
| 06 Jul 17 | R. Stearman Richard Stearman |  FulhamFUL | → | Sheffield UnitedSHU | Undisclosed |
| 04 Jul 17 | G. Long George Long | Sheffield UnitedSHU | → |  AFC WimbledonWIM | Loan |
| 01 Jul 17 | B. Whiteman Ben Whiteman | Sheffield UnitedSHU | → |  Doncaster RoversDON | Loan |
| 31 Jan 17 | A. Ramsdale Aaron Ramsdale | Sheffield UnitedSHU | → |  AFC BournemouthBOU | Undisclosed |
| 17 Jan 17 | Joe Riley |  Manchester UnitedMAN | → | Sheffield UnitedSHU | Loan |
| 13 Jan 17 | D. Lafferty Danny Lafferty |  BurnleyBUR | → | Sheffield UnitedSHU | Undisclosed |